1. Field of the Invention
The present invention relates to a cooling system having a refrigerator and a maintenance timing determination method.
2. Description of the Related Art
Generally, a cooling system for cooling an object to be cooled at a cryogenic temperature (an extremely low temperature) is provided with a refrigerator for cooling the object. As for such a refrigerator, a GM (Gifford-McMahone) refrigerator, which has a high reliability and is capable of being miniaturized, is used in many cases.
The GM refrigerator includes components that degrade over time such as sliding parts, filters, etc. In association with the temporal degradation of those component parts, the refrigeration capacity of the refrigerator is degraded. Thus, a GM refrigerator needs to be subjected to a maintenance operation.